Enhancement of the NH3-SCR catalytic activity of MnTiOx catalyst by the introduction of Sb.

Sb was used as the additive to enhance the NH 3 -SCR performance of MnTiO x catalyst. Experimental results revealed that MnSbTiO x -0.2 demonstrated outstanding NH 3 -SCR activity in a wide temperature window (100–400 ℃) and high resistance to SO 2 . Characterization results indicated the introduction of Sb into MnTiO x catalyst could improve the dispersity of active species and generate more surface acid sites, Mn 4+ and surface adsorbed oxygen species. In situ DRIFT spectra proved that the presence of Sb in MnSbTiO x -0.2 catalyst could form new Brønsted acid sites, along with the increased surface Lewis acidity. The improved adsorption of NH 3 and NO x species over MnSbTiO x -0.2 catalyst had a stimulating effect on the NH 3 -SCR reaction over it through Langmuir−Hinshelwood (L-H) route. Moreover, Sb species in MnSbTiO x -0.2 could improve the reactivities of ad-NH 3 and ad-NO x species in SCR reaction. All these factors contributed to the excellent performance of MnSbTiO x -0.2 catalyst. [ABSTRACT FROM AUTHOR]